[Tests-Only] Add webUI tests for preview of image files with media viewer

tests/acceptance/expected-failures-with-oc10-server.txt

@@ -1,8 +1,8 @@
 # this file contains the scenarios from web tests that are currently expected to fail on oC10
 #
 # https://github.com/owncloud/ocisissues/1106 media viewer does not support mp3 files
-webUIPreview/imageMediaViewer.feature:78
-webUIPreview/imageMediaViewer.feature:85
+webUIPreview/imageMediaViewer.feature:81
+webUIPreview/imageMediaViewer.feature:88
 #
 # https://github.com/owncloud/web/issues/4564 authentication dialog appears when user is deleted
 webUILogin/login.feature:62

tests/acceptance/expected-failures-with-ocis-server-owncloud-storage.txt

@@ -1,8 +1,8 @@
 # this file contains the scenarios from web tests that are currently expected to fail on OCIS with owncloud storage
 #
 # https://github.com/owncloud/ocisissues/1106 media viewer does not support mp3 files
-webUIPreview/imageMediaViewer.feature:78
-webUIPreview/imageMediaViewer.feature:85
+webUIPreview/imageMediaViewer.feature:81
+webUIPreview/imageMediaViewer.feature:88
 #
 # https://github.com/owncloud/web/issues/4564 authentication dialog appears when user is deleted
 # https://github.com/owncloud/ocis/issues/1129 login error page loops when logged in user is deleted
@@ -185,7 +185,10 @@ webUISharingInternalUsersBlacklisted/shareWithUsers.feature:90
 webUILogin/login.feature:52
 #
 # Image-Media-Viewer-Issue
-webUIPreview/imageMediaViewer.feature:30
+webUIPreview/imageMediaViewer.feature:33
+#
+#https://github.com/owncloud/web/issues/4296 media viewer does not display jpeg file
+webUIPreview/imageMediaViewer.feature:15
 #
 # webUI-Private-Links
 webUIPrivateLinks/accessingPrivateLinks.feature:8

tests/acceptance/features/webUIPreview/imageMediaViewer.feature

@@ -3,13 +3,16 @@ Feature: display image in media viewer on the webUI
   Background:
     Given user "user1" has been created with default attributes
 
-
-  Scenario: preview of image with media viewer is possible
-    Given user "user1" has uploaded file "testavatar.jpg" to "testavatar.jpg"
+Scenario Outline: preview of image files with media viewer is possible
+    Given user "user1" has uploaded file "<image-file>" to "<image-file>"
     And user "user1" has logged in using the webUI
-    When the user views the file "testavatar.jpg" in the media viewer using the webUI
-    Then the file "testavatar.jpg" should be displayed in the media viewer webUI
-
+    When the user views the file "<image-file>" in the media viewer using the webUI
+    Then the file "<image-file>" should be displayed in the media viewer webUI
+    Examples:
+      | image-file      |
+      | testavatar.jpg  |
+      | testavatar.png  |
+      | testavatar.jpeg |
 
   Scenario: preview of video with media viewer is possible
     Given user "user1" has uploaded file "test_video.mp4" to "test_video.mp4"